The most persistent and intractable cause of infant and child mortality and morbidity in the US remains preterm and low birthweight deliveries. Pregnant women in the United States experience the highest incidence of these complications among developed countries. Even more disturbing is the observation that immigrant Hispanic women experience worsening birth outcomes the longer they live here, despite increasing access to prenatal care, improved socio-economic status and better education. The purpose of this study is to identify the potential acculturation-related risk factors for preterm and low birthweight (PTLBW) delivery among Hispanic women of varying lengths of US residency. It is hypothesized that changes in factors associated with acculturation, such as poor nutritional intake, job stress and occupational exposures to pesticides or other hazards, and certain types of genital infections, can best explain the worsening of pregnancy outcomes among Hispanic immigrant women.